Quiz Discussion

A person travels three equal distance at a speed of x km/hr, y km/hr and z km/hr respectively. What is the average speed for the whole journey ?

• 1]

  \(\frac{{xyz}}{{3\left( {xy + yz + zx} \right)}}\)    km/hr

• 2]

  \(\frac{{xyz}}{{\left( {xy + yz + zx} \right)}}\)    km/hr

• 3]

  \(\frac{{\left( {xy + yz + zx} \right)}}{{xyz}}\)    km/hr

• 4]

  \(\frac{{3xyz}}{{\left( {xy + yz + zx} \right)}}\)    km/hr

A is 10 miles west of B. C is 30 miles north of B. D is 20 miles east of C. What is the distance from A to D ?

• 1]

  10 miles

• 2]

  30 miles

• 3]

  \(10\sqrt {10}  \) miles

• 4]

  \(10\sqrt {13}  \) miles

• 5]

  \(30\sqrt {2}  \) miles

A car traveling with \(\frac{5}{7}\) of its usual speed covers 42 km in 1 hr 40 min 48 sec. What is the usual speed of the car?

• 1]

  \(17\frac{6}{7}\) km/hr

• 2]

  35 km/hr

• 3]

  25 km/hr

• 4]

  30 km/hr

If A travels to his school from his house at the speed of 3 km/h, then he reaches the school 5 minutes late. If he travels at the speed of 4 km/h, he reaches the school 5 minutes earlier than school time. The distance of his school from his house is:

• 1] 1 km
• 2] 2 km
• 3] 3 km
• 4] 4 km

A train started from station A and proceeded towards station B at a speed of 48 km/hr. Forty-five minutes later another train started from station B and proceeded towards station a at 50 km/hr. If the distance between the two stations is 232 km, at what distance from station A will the trains meet ?

• 1] 108 km
• 2] 132 km
• 3] 144 km
• 4] None of these

Two trains start simultaneously from two stations Howrah and Delhi, respectively towards each other on the same track. The distance between the two stations is 560 km and the speeds of trains are 30 kmph and 40 kmph.

• 1] 70 km
• 2] 560 km
• 3] 640 km
• 4] 650 km
• 5] None of these

A cyclist drove one kilometre, with the wind in his back, in 3 minutes and drove the same way back, against the wind, in 4 minutes. If we assume that the cyclist always puts constant force on the pedals, how much time would it take him to drive 1 km without wind ?

• 1]

  \(2\frac{1}{3}\) min

• 2]

  \(2\frac{3}{7}\) min

• 3]

  \(3\frac{3}{7}\) min

• 4]

  \(3\frac{7}{12}\) min

A and B travel the same distance at speed of 9 km/hr and 10 km/hr respectively. If A takes 36 min more than B, the distance travelled by each is :

• 1] 48 km
• 2] 54 km
• 3] 60 km
• 4] 66 km

Two trains of equal length, running in opposite directions, pass a pole in 18 and 12 seconds. The trains will cross each other in:

• 1] 14.4 seconds
• 2] 15.5 seconds
• 3] 18.8 seconds
• 4] 20.2 seconds

In a 100m race, Kamal defeats Bimal by 5 seconds. If the speed of Kamal is 18 kmph, then the speed of Bimal is:

• 1] 15.4 kmph
• 2] 14.5 kmph
• 3] 14.4 kmph
• 4] 14 kmph